1. Field of the Invention
The present invention relates to a laminated structural type balun that is a component converting balanced signals and unbalanced signals mutually.
2. Description of the Related Art
A balun is a component converting balanced signals and unbalanced signals mutually. Some baluns use a high pass filter (HPF) and a low pass filter (LPF) in combination (see Japanese Patent Application Laid-open No. 2000-236227 and Japanese Patent Application Laid-open No. H10-200360, for example). A balun having this type of structure has a conversion input and a conversion output that are electrically connected. For this reason, for example, as compared with an electromagnetic coupling type balun, the insertion loss is smaller, and the matching of input and output impedances is also possible at the same time as balanced and unbalanced signal conversion. In addition, Japanese Patent Application Laid-open No. 2000-236227 and Japanese Patent Application Laid-open No. H10-200360 decribe a laminated structural balun (laminated structural type balun) in which a conductor pattern is formed between insulating layers.
The baluns described in Japanese Patent Application Laid-open No. 2000-236227 and Japanese Patent Application Laid-open No. H10-200360 leave room for improvement in electrical properties.